I. Field of the Invention
The present invention relates generally to fluid couplings.
II. Description of the Prior Art
In many fluid systems, such as the hydraulic brake system of an automotive vehicle, it is essential that any fluid couplings contained within the system, as well as the fluid tubes themselves, be leak free. For this reason, many such systems utilize metal tubing which is not only capable of containing high pressure, but is also leak free unless damaged.
Many of these previously known systems utilize metal tubing having an outwardly flared portion at the end of the tube. A fluid coupling is then used to secure two flared ends of the metal tubing together in order to complete the fluid connection.
The previously known fluid connectors used in automotive brake systems typically include a three-piece design. A first fluid connector having an externally threaded portion with an outwardly flared surface at one end is disposed over each of the metal tubings so that the outwardly flared ends of each connector register with the outwardly flared portion on their respective tube. An internally threaded coupling includes a throughbore which is threaded at each end. This coupling also includes two outwardly facing annular abutment surfaces within the throughbore. Thus, when the externally threaded fluid connectors are threadably connected to the internally threaded coupling, upon tightening, the flared ends of the tube are compressed between the two externally threaded fluid connectors and the abutment surfaces formed within of the internally threaded coupling throughbore.
In order to form the coupling, both the externally threaded fluid connectors as well as the internally threaded coupling have a hexagonal outer surface to facilitate rotation and tightening of the coupling with a conventional wrench. Typically, one externally threaded fluid connector is first tightened into the fluid coupling and thereafter the second fluid connector is tightened into the other end of the internally threaded fluid coupling.
A primary disadvantage of this fluid coupling assembly, however, is that two separate tightening operations are required in order to complete the fluid coupling assembly, i.e. the first tightening operation of the first externally threaded connector to the internally threaded coupling and, secondly, tightening the second externally threaded connector to the opposite end of the internally threaded coupling. The requirement of two tightening operations thus increases the overall assembly time of the fluid coupling assembly. Furthermore, since automotive brake systems typically comprise numerous fluid coupling assemblies, the requirement of two tightening operations for each coupling assembly appreciably increases the assembly labor cost and cycle time of the vehicle.
A still further disadvantage is that these previously known coupling assemblies are both heavy and relatively long. Since the coupling assembly is oftentimes suspended by the tube itself, the weight of the coupling assembly is oftentimes suspended by the tube itself, the weight of the coupling assembly may result in tube fatigue and/or rattling. Additionally, such coupling assemblies are difficult to use in tight packaging conditions.